Answer:
100 J, 225 J
Explanation:
The kinetic energy of an object is given by:

where
m is the mass of the object
v is the velocity of the object
In this problem, the initial kinetic energy of the object is
K = 25 J
Then, the velocity is doubled, which means
v' = 2v
Therefore, the new kinetic energy will be

Therefore, the kinetic energy has quadrupled:

Later, the velocity is tripled, which means
v'' = 3v
Therefore, the new kinetic energy will be

Therefore, the kinetic energy has increased by a factor of 9:

Answer:
The moment arm is 0.6 m
Explanation:
Given that,
First force 
Second force 
Distance r = 0.2 m
We need to calculate the moment arm
Using formula of torque

So, Here,

We know that,
The torque is the product of the force and distance.
Put the value of torque in the equation


Where,
=First force
=First force
=Second force
= distance
Put the value into the formula


Hence, The moment arm is 0.6 m
<u>Voltage:</u>
It is basically the difference between the charges of the materials on the ends of the Wire
<em>also known as potential difference</em>
It is very similar to the movement of air, it moves from higher density to lower density. in this case, the change in density is the potential difference
So, since voltage is the difference between the charge available on the ends of a wire. Even if the wire splits in parallel circuit, the difference of the charges remains the same
<em>the more the potential difference, the faster electrons will move to the material with lower charge</em>
<u>Current:</u>
Current is the amount of electrons moving through a cross-section of a wire in a period of time
So basically, it is the amount of electrons that move across a given point on a wire in a period of time
If the wire splits, we will have the same amount of electrons moving through as they would if the wire was not split but now, the electrons passing are divided and hence, if we measure the current after the split, we will find that we have a lower current
that's because we have less charge moving through the cross-section of the wire since some of those electrons are moving through a different wire
That's why the current splits in a parallel circuit
It is very difficult for an atom to accept a proton. It can only be done under very special circumstances. So A and C are both incorrect. I don't see how D is possible. The atom does lose 1 electron, but how it gets 21 is think air.
The answer is B which is exactly what happens.